*cg-timer-resolution*

On GTK, timer events do not wake up the event-handling process as
other events do, and so we must periodically check for them
proactively. This creates a trade-off where checking less often makes
timers less responsive, while checking more often slows other activity
down as the event-handling process is run frequently to check for
timer events.

The default value should be an adequate compromise for most
applications, but if you need timers that respond with greater than
tenth-of-a-second accuracy, then you would need to set this variable
to a smaller value. Or, if you don't make much use of Common Graphics
timers, you might want to set it to a larger value to see if that
increases overall performance.